ALSA: info: Move card id proc creation into info.c

The creation of card's id proc file can be moved gracefully into
info.c.  Also, the assignment of card->proc_id is superfluous and can
be dropped.  So let's do it.

Basically this is no functional change but code refactoring, but one
potential behavior change is that now it returns properly the error
code from snd_info_card_register(), which is a good thing (tm).
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

include/sound/core.h

@@ -120,7 +120,6 @@ struct snd_card {
 	struct list_head ctl_files;	/* active control files */
 
 	struct snd_info_entry *proc_root;	/* root for soundcard specific files */
-	struct snd_info_entry *proc_id;	/* the card id */
 	struct proc_dir_entry *proc_root_link;	/* number link to real id */
 
 	struct list_head files_list;	/* all files associated to this card */

sound/core/info.c

@@ -504,6 +504,14 @@ int __exit snd_info_done(void)
 	return 0;
 }
 
+static void snd_card_id_read(struct snd_info_entry *entry,
+			     struct snd_info_buffer *buffer)
+{
+	struct snd_card *card = entry->private_data;
+
+	snd_iprintf(buffer, "%s\n", card->id);
+}
+
 /*
  * create a card proc file
  * called from init.c
@@ -521,7 +529,8 @@ int snd_info_card_create(struct snd_card *card)
 	if (!entry)
 		return -ENOMEM;
 	card->proc_root = entry;
-	return 0;
+
+	return snd_card_ro_proc_new(card, "id", card, snd_card_id_read);
 }
 
 /*

sound/core/init.c

@@ -100,33 +100,6 @@ int (*snd_mixer_oss_notify_callback)(struct snd_card *card, int free_flag);
 EXPORT_SYMBOL(snd_mixer_oss_notify_callback);
 #endif
 
-#ifdef CONFIG_SND_PROC_FS
-static void snd_card_id_read(struct snd_info_entry *entry,
-			     struct snd_info_buffer *buffer)
-{
-	struct snd_card *card = entry->private_data;
-
-	snd_iprintf(buffer, "%s\n", card->id);
-}
-
-static int init_info_for_card(struct snd_card *card)
-{
-	struct snd_info_entry *entry;
-
-	entry = snd_info_create_card_entry(card, "id", card->proc_root);
-	if (!entry) {
-		dev_dbg(card->dev, "unable to create card entry\n");
-		return -ENOMEM;
-	}
-	snd_info_set_text_ops(entry, card, snd_card_id_read);
-	card->proc_id = entry;
-
-	return snd_info_card_register(card);
-}
-#else /* !CONFIG_SND_PROC_FS */
-#define init_info_for_card(card)
-#endif
-
 static int check_empty_slot(struct module *module, int slot)
 {
 	return !slots[slot] || !*slots[slot];
@@ -493,7 +466,6 @@ static int snd_card_do_free(struct snd_card *card)
 	snd_device_free_all(card);
 	if (card->private_free)
 		card->private_free(card);
-	snd_info_free_entry(card->proc_id);
 	if (snd_info_card_free(card) < 0) {
 		dev_warn(card->dev, "unable to free card info\n");
 		/* Not fatal error */
@@ -797,7 +769,10 @@ int snd_card_register(struct snd_card *card)
 	}
 	snd_cards[card->number] = card;
 	mutex_unlock(&snd_card_mutex);
-	init_info_for_card(card);
+	err = snd_info_card_register(card);
+	if (err < 0)
+		return err;
+
 #if IS_ENABLED(CONFIG_SND_MIXER_OSS)
 	if (snd_mixer_oss_notify_callback)
 		snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);